Catheters are used for many medical purposes. The present invention is not limited to a specific type of catheter, rather a method of making the catheter and the resulting product. Examples of catheters and procedures are addressed below for the sake of background.
In typical PTA or PTCA procedures, a guiding catheter is percutaneously introduced into the cardiovascular system of a patient and advanced through the aorta until the distal end is in the desired (coronary) artery. Using fluoroscopy, a guide wire is then advanced through the guiding catheter and across the site to be treated in the coronary artery. An over the wire (OTW) balloon catheter is advanced over the guide wire to the treatment site. The balloon is then expanded to reopen the artery. The OTW catheter may have a guide wire lumen which is as long as the catheter or it may be a rapid exchange catheter wherein the guide wire lumen is substantially shorter than the catheter. Alternatively, a fixed wire balloon may be used. This device features a guide wire which is affixed to the catheter and cannot be removed.
To help prevent arterial closure, repair dissection, or prevent restenosis, a physician can implant an intravascular prosthesis, or a stent, for maintaining vascular patency inside an artery or other vessel at the lesion.
Stents are also used for a variety of other purposes including maintaining the patency of any physiological conduit including arteries, veins, vessels, the biliary tree, the urinary tract, the alimentary tract, the tracheobronchial tree, the genitourinary system, and the cerebral aqueduct.
The stent may either be self-expanding or balloon expandable. For the latter type, the stent is often delivered on a balloon and the balloon is used to expand the stent. The self-expanding stents may be made of shape memory materials such as nitinol or constructed of regular metals but of a design which exhibits self expansion characteristics.
The present invention is directed to the area of constructing catheters and other medical devices such as described above. Each catheter has many parts which must be interconnected with high accuracy and precision. Typically parts are adhered or thermally bonded together. Using retaining sleeves as an example (examples of which may be found in U.S. Pat. No. 4,950,227, U.S. Pat. No. 6,221,097, U.S. Pat. No. 6,068,634, U.S. Pat. No. 5,980,530, U.S. Pat. No. 5,968,069 and U.S. Pat. No. 5,044,726), welding may be accomplished by heating the retaining sleeve or by applying laser radiation to the retaining sleeve at a wavelength absorbed by the retaining sleeve. CO2 lasers have proven to be particularly useful in this regard. Adhering and Welding methods are well known in the industry. An example of the use of laser welding may be found in U.S. application Ser. No. 09/684,255.
All U.S. patents and applications all other published documents mentioned anywhere in this application are incorporated herein by reference in their entirety.
Without limiting the scope of the invention in any way, the invention is briefly summarized in some of its aspects below.